1. Field of the Invention
The present invention relates generally to vehicle safety seats for children, and more specifically to a rear facing vehicle safety seat having a seat unit detachably engageable with a corresponding base unit, wherein the seat unit is capable of moving relative to portions of the base unit during an accident to dampen sudden and potentially dangerous forces applied to the seat as a result of such accident.
2. Description of the Related Art
Child safety seats which are specifically adapted for use in a vehicular environment are well known in the art. Many such safety seats are secured to an existing vehicle car seat, with the child being placed within the safety seat to secure the child during travel. These prior art safety seats are typically in the form of a child/infant car seat or a booster seat. A child car seat is typically secured directly to the vehicle, such as by the vehicle's seat belt system or directly to the frame of the vehicle using hooks, and other attachment mechanisms and systems. The car seat is also outfitted with its own, dedicated restraint or harness system to secure the child therein, such harness system generally being referred to as five-point harness system.
Booster seats are typically used for older children. This type of seat meets all government standards as to safety and is appropriate for children from toddler up to a particular size, such booster seats thus being used to accommodate children too large to fit into the above-described car seat, but still too small to properly use the restraining systems of standard automobiles, that is, the seat and/or harness shoulder straps in these systems. There are currently known booster seats which include many of the same structural features as car seats, including a dedicated harness system as well as attachment mechanisms such as an arrangement of straps/tethers operative to facilitate the engagement thereof to corresponding rigid attachment points provided within the vehicle. However, there are also booster seats that are not outfitted with a dedicated harness system or an attachment mechanism operative to facilitate the attachment thereof to corresponding rigid attachment points of the vehicle, such booster seats simply being used in concert with the existing seat belt system of the vehicle to restrain the child therein. For ease of discussion, child car seats and booster seats which are adapted for use with children within prescribed size/weight ranges and outfitted with attachment mechanism specifically adapted to engage corresponding rigid attachment points of the vehicle will collectively be referred to as “child safety seats.”
Many countries around the world have standardized how a child safety seat is to be secured to a vehicle seat and how movement of the safety seat is controlled in the event of an impact to improve the overall safety of safety seats in vehicles. A system called Lower Anchors and Tethers for Children (LATCH) is commonly used for this purpose, which includes two lower anchor attachments and a top tether. The term is often used generically to refer only to the pair of fixed lower loop shaped anchors built into the bight or crack between the seat back and seat cushion. The LATCH system was originally called ISOFIX, which is a term still used in Europe. Canada, employs a similar standard called the Universal Anchorage System (UAS). It has also been called the Universal Child Safety Seat System or UCSSS. All of foregoing systems refer to the same universal anchorages that started to appear on car models starting in about the year 2000. These are now required by law in the United States for almost all model year 2003 and later vehicles.
When a LATCH system is used, existing seatbelts are no longer necessary to install the child safety seat since it is mounted directly to the vehicle via the metal loops using webbing or a “rigid” connector. The safety seat often includes releasable clips to engage with the metal loops of the LATCH system. This makes it easier to safely install safety seats, and to make it more universal among car seats and vehicles. Compatible corresponding LATCH coupling systems are now commonly found on child safety seat bases, including rear-facing, front-facing and combination car/booster seats. Further details of the LATCH system need not be discussed in further detail as it is so well known in the art. It should also be understood that the LATCH system, although a preferred method, is just one way to secure a child safety seat to a supporting vehicle seat.
In view of the requirement to fixedly secure child safety seats to a supporting vehicle seat, there are challenges in the industry for control over the movement of the seat itself in the event of an impact to the vehicle, such as during an accident. More specifically, there is a concern as to movement of the safety seat in such conditions because excessive forces exerted can cause injury to a child therein.
For example, when a child safety seat is fixedly connected to a vehicle, an accident may cause impact forces that may result in very sudden and abrupt movements to the child. It has been shown that these sudden and abrupt movements to a child in a child safety seat is more likely to injure a child than movements that are less abrupt. For example, sudden stopping of a vehicle and the sudden stopping of forces to a child safety seat is more likely to injure a child than where such forces are stopped in a slower or decelerated fashion.
In view of this, some child safety seats are designed with features that in some way decelerate the child's movement relative to the movement of the vehicle. This helps reduce resulting impact forces to the child and helps prevent injuries to a child. This deceleration is often called “ride down” where some type of load limiting is provided to manage the deceleration rate of the child car seat.
Although having “ride down” capabilities in a child safety seat may provide significant safety benefits, there have been difficulties in incorporating such capabilities into the structure of the safety seat. Indeed, the difficulties include creating a safety seat which remains substantially stationary to a vehicle during normal use, while at the same time, has the ability to enable a limited amount of movement for purposes of dampening forces in the event of an accident. The difficulties are further complicated by a desire to incorporate recline adjustability into the safety seat, which would add another species of movement, albeit user actuated, into the seat design. Many of these design challenges have been addressed in those exemplaryimplementations of ride down capability within safety seats as found in Applicant's U.S. Pat. No. 8,632,124 entitled Reclining Ride Down Child Seat and U.S. Patent Publication No. 2012/0319442 entitled Crash Indication System for a Reclining Ride Down Child Seat, the disclosures of which are incorporated herein by reference.
However, there is still a need for a child safety seat, and notably a rear facing safety seat for an infant, that includes a ride down capability while also being able to provide recline angle adjustment for further comfort of the child without sacrificing safety of the child. Various aspects of the present invention address this particular need, as will be discussed in more detail below.